My favorite are all the morons who got the same talking point about democracy and the 14 million Biden primary voters. It's sort of like wearing the red hat, easy way to identify the morons.
When Democrats, independents and some Republicans talk about protecting American democracy, they're talking about federal elections, most specifically the election of the president. It's in refence to the different methods that Trump tried to use to steal the election in 2020. Finding votes in GA, fake electors in numerous states, interrupting the certification and trying to hang Pence on 1/6. The threat is around the groundwork being laid in order to be successful the next time.
They aren't talking about how the Democratic party selects their nominees, we are all already aware that the Democratic party doesn't use a simple democratic vote to make those selections, we're aware of Super Delegates, we're aware that parties can make their own rules and their own processes. That's always been the case. People who are concerned about the state of democracy in America are talking about our actual elected positions, not party nominations.